The tracer diffusivity of Co in polycrystalline samples was studied between 600 and 950C, under an O partial pressure of 1atm, by using serial sectioning or secondary ion mass spectrometry methods (figure 60). It was found that the present results (table 23) fell upon the same Arrhenius curve:

D(cm2/s) = 1.4 x 101exp[-280(kJ/mol)/RT]

as did previous data. Measurements of Co and Ni diffusion in the c-axis direction of monocrystalline platelets indicated that there was a much greater diffusional anisotropy in the case of Co.

Site Selectivity and Cation Diffusion in YBa2Cu3O7-δ. J.L.Routbort, S.J.Rothman, N.Chen, J.N.Mundy, J.E.Baker: Physical Review B, 1991, 43[7], 5489-97